Did Marie Curie use an observational study, a controlled experiment, or a mathematical model when investigating the atom?

Read the excerpt from jefferson’s inaugural address. “with all these blessings, what more is necessary to make us a happy and a prosperous people? still one thing more, fellow citizens—a wise and frugal government, which shall restrain men from injuring one another, shall leave them otherwise free to regulate their own pursuits of industry and improvement, and shall not take from the mouth of labor the bread it has earned.” which identifies a presidential action taken by jefferson that reflects his attempt to realize the goals expressed in the excerpt? a. changing the tax system to reduce the size of government b. purchasing the louisiana territory from france c. creating a national prison system to incarcerate criminals d. improving social programs to feed the poor